Sulfurized cutting oil compositions



SULFURIZED CUTTING OIL COMPOSITIONS Jacobus Rinse, Bernardsville, N. Jassignor to Sulfo-Inc., Elizabeth, N. J., a corporation of New .lerseyNo Drawing. Application January 19, 1954 Serial No. 405,050

6 Claims. (Cl. 252-31) This invention relates to sulfurized cutting oilsand more specifically to such oils of improved properties in which thesuspension of the finely divided sulfur is caused and maintained by thepresence of a small amount of an ester of hydroxy stearic acid.

Cutting oils of the type here involved are described in the UnitedStates patent of Victor R. Abrams, No. 2,157,379, the sulfur beingsuspended in the cutting oil base by means of a hydrogenated castor oilwax which provides a free flowing gelatinous mass. Although thesecutting oils serve their intended purpose quite well, they do notprovide ideal performance, particularly in rela tion to sedimentation.In addition, the suspending agent is of limited availability. Othercutting oils used in industry are even more deficient as to thissedimentation quality.

An object of the present invention is to provide cutting oils havinghighly efiective improved properties. Another object is to producecutting oils which remain stable and homogeneous over long periods oftime and which are capable of substantial dilution with mineral oilwithout loss, or appreciable loss, of stability.

The sulfurized cutting oils of the present invention are composed of amineral oil base, finely divided sulfur and a suspending agent composedof an ester of any of the hydroxy stearic acids known to industry amongwhich there may be mentioned the alphaand beta-hydroxy, and the 10-,11-, and 12-hydroxy stearic acids. These are esterified with a mono-, ora polyvalent alcohol preferably those of low and intermediate chainlength as up to eight carbon atoms to provide a monoester. Specifically,there may be utilized esters from aliphatic alcohols as methyl, hexyl,and ethylene glycol; aromatic alcohols such as benzyl; and cyclicalcohols such as cyclohexanol.

These hydroxy fatty acids may be derived by any of the known processes,and can be satisfactorily prepared either by hydroxylating stearic acidor by separation from castor oil. The alcohol used must produce estersof the acids which are sufliciently soluble in mineral oil.

No change from known practices as to the nature of the oil base or ofthe sulfur components is required either as to quality or proportions.As to the oil, the usual mineral or petroleum oils are contemplated, asthose having a viscosity of 100-300 seconds. As to the sulfur component,flowers of sulfur and other finely divided sulfurs of particle sizesknown to be suitable in providing cutting oils, are contemplated. Thesulfur content of the cutting oil will usually amount to from about 1 to10%, but the oil can be diluted further by the addition of more of themineral oil base.

The novel cutting oils of the present invention composed predominantlyof the mineral oil base require only a small amount of the ester toproduce and maintain the suspension of the sulfur. The proportionrequired in any particular formulation depends upon the viscosity of theoil, the proportion and particle size of United States Patent 2,829,101Patented Apr. 1,1958

the sulfur, the suspending power of the particular ester used and theconditions of use intended for the cutting oil, and can be determined bytest. The amount added, of course, should be large enough to effect thestable suspension without at the same time preventing the degree of freeflow required of the cutting oil during the intended use. Usually aproportion amounting to about 2 to 10 percent gives desirable results. 7

The sulfurized cutting oils may be compounded without difiiculty in anystirring or agitating device. The components may be added in any orderbut a procedure serving well involves first dispersing the ester in themineral oil and then adding the finely divided sulfur as such ordispersed in a lighter or a heavier hydrocarbon oil.

Although the cutting oils of the invention serve well their intendedpurposes without any additions, it is realized that for specific reasonsarising in their use throughout the industry it will be desirable to addother components, as lard oil or other animal oils; vegetable oils, ascotton seed oil, rosin or rosin oil; hydrogenated oils, turpentine,carbon tetrachloride, kerosene, sulphonated lard oil, soaps or evenwater or graphite.

Example 1 To parts of mineral oil (200 sec. vise.) there are added 5parts of methyl l2-hydroxy stearate. The mixture is heated until acompletely homogeneous mass is obtained. T hereupon, 15 parts of flowersof sulfur are mixed in and a paste is obtained which remains homogeneousduring storage. When it is to be used as a cutting oil, it can bediluted with -200% of its weight with additional mineral oil.

Example 2 To 6.25 parts of ethylene glycolate of 10-, 11- or 12- hydroxystearic acid, there are added 250 parts of mineral oil (100 sec. visc.).The mixture is heated until a homogeneous mass is obtained. After themass cools, 25 parts of sulfur are added and stirred in. The resultingsuspension remains homogeneous for more than six weeks. It can bediluted with an equal weight of the same cutting mineral oil base andthe sulfur will not settle out from the suspension formed even if storedfor an additional six weeks.

Example 3 Twelve and one-half parts of butylhydroxy stearate aredissolved by mixing in 250 parts of hot mineral oil (200 sec. visc.).After the mass cools, 25 parts of flowers of sulfur are added andstirred in. The resulting suspension remains stable for a period of morethan six weeks and performs well as a cutting oil after dilution withtwo times up to as much as five times more mineral oil.

It should be understood that the present invention is not limited to thespecific compounds or materials disclosed herein but that it extends toall equivalents which will occur to those skilled in the art uponconsideration of the terms of the claims appended hereto.

I claim:

1. A sulfurized cutting oil comprising a mineral oil having thepropertiesrequired for use in cutting oils containing finely dividedsulfur suspended therein by the presence of a small amount of an esterof hydroxy stearic acid having up to eight carbon atoms in theesterifying radical.

2. A stable, free-flowing, sulfurized cutting oil comprising a cuttingoil base composed of mineral oil, flowers of sulfur suspended thereinand a suspending agent consisting of a mono-ester of hydroxy stearicacid in a quantity which stably suspends said sulfur particles whilepermitting free flow of the cutting oil during use.

3. A sulfurized cutting oil comprising a mineral oil having theproperties required for use in cutting oils containing finely dividedsulfur suspended therein by the presence of a small amount of a lowermolecular alkyl ester of hydroxy stearic acid.

4. A sulfurized cutting oil comprising a mineral oil having theproperties required for use in cutting oils containing finely dividedsulfur suspended therein by the presence of a small amount of the butylester of hydroxy stearic acid.

5. A sulfurized cutting oil comprising a mineral oil having theproperties required for use in cutting oils containing finely dividedsulfur suspended therein by the presence of a small amount of theethylene glycolate of hydroxy stearic acid.

6. A sulfurized cutting oil comprising a mineral oil having theproperties required for use in cutting oils containing finely dividedsulfur suspended therein by the presence of a small amount of the methylester of hydroxy stearic acid.

References Cited in the file of this patent UNITED STATES PATENTS1,913,300 Abrams June 6, 1933 2,157,379 Abrams May 9, 1939 FOREIGNPATENTS 329,266 Great Britain May S, 1930 OTHER REFERENCES SyntheticDetergents, by McCutcheon, MacNair- Dorland Co., New York, N. Y., 1950,pages 46 and 47.

Gregory: Uses and Application of Chemicals and Related Materials,Reinhold Publishing Corporation, New York, N. Y., 1939, vol. 1, page.322.

1. A SULFURIZED CUTTING OIL COMPRISING A MINERAL OIL HAVING THEPROPERTIES REQUIRED FOR USE IN CUTTING OILS CONTAINING FINELY DIVIDEDSULFUR SUSPENDED THEREIN BY THE PRESENCE OF A SMALL AMOUNT OF AN ESTEROF HYDROXY STEARIC SAID HAVING UP TO EIGHT CARBON ATOMS IN THEESTERIFYING RADICAL.